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            <p>
                <span class="bold"><strong>What priorities should
                threads/tasks executing Berkeley DB functions be
                given?</strong></span>
            </p>
            <p>
                Tasks executing Berkeley DB functions should have
                the same, or roughly equivalent, system priorities.
                For example, it can be dangerous to give tasks of
                control performing checkpoints a lower priority than
                tasks of control doing database lookups, and
                starvation can sometimes result. 
            </p>
          </li>
          <li>
            <p>
                <span class="bold"><strong>Why isn't the C++ API exception
                safe?</strong></span>
            </p>
            <p> 
                The Berkeley DB C++ API is a thin wrapper around
                the C API that maps most return values to exceptions,
                and gives the C++ handles the same lifecycles as their
                C counterparts. One consequence is that if an
                exception occurs while a cursor or transaction handle
                is open, the application must explicitly close the
                cursor or abort the transaction. 
            </p>
            <p> 
                Applications can be simplified and bugs avoided by
                creating wrapper classes around <a href="../api_reference/C/dbc.html" class="olink">DBC</a> and <a href="../api_reference/C/txn.html" class="olink">TXN</a> that
                call the appropriate cleanup method in the wrapper's
                destructor. By creating an instance of the wrappers on
                the stack, C++ scoping rules will ensure that the
                destructor is called before exception handling unrolls
                the block that contains the wrapper object. 
            </p>
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            <p>
                <span class="bold"><strong> How do I handle a "pass 4"
                    error when trying to run one of the example
                    Performance Event Monitoring scripts on my Linux
                    system? The library was configured with
                    <code class="literal">--enable-dtrace</code> and built
                    without error. </strong></span>
            </p>
            <p>
                A Linux installation can have SystemTap support for
                kernel probe points without including the kernel
                "utrace" module needed to use userspace probes. Pass 4
                errors can occur when this required userspace support
                is not present.
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            <p>
                <span class="bold"><strong> I have a program with multiple
                    threads running on multi-core systems, and it uses
                    a shared DB handle for all the threads. The
                    program does not behave as well as I expect and I
                    see a lot of contention on the dbp-&gt;mutex, what
                    should I do to reduce this contention ?
                </strong></span>
            </p>
            <p> 
                When running multi-threaded program on a
                multi-core/multi-processor system, we suggest using a
                DB handle per thread instead of using a shared handle
                accorss threads. Since many operations(like creating
                cursors) requires to lock the DB handle first, and if
                using a shared handle, there could be a lot of lock
                contention on the handle. 
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